1. Field of the Invention
The present invention relates to the repurification and recovery of a solvent, and more particularly relates to a method of and an apparatus for purifying a solvent that has been used in the plants manufacturing certain liquid crystal devices or certain integrated circuit chips or the like and contains considerable amounts of low boiling fractions and high boiling fractions.
2. Prior Art
Various resists are used to manufacture the liquid crystal devices or integrated circuits (IC), and the latter are washed with a solvent so as to remove those resists. The solvent may be a water insoluble one or a water soluble one. The water soluble solvent is convenient to wash those devices or circuits, subsequent to removal thereof.
Those solvents gradually lose their washing efficiency or power when used repeatedly to wash the liquid crystal or the like electronic devices. This is because the low boiling fractions such as water as well as the high boiling ones such as the resist components are accumulated in the solvent.
Therefore, it has been a common practice either to replace at once the dirty or impure solvent with a fresh one, or to add the latter at a constant rate.
Thus, the dirty solvent has been discarded from the abovementioned plants either intermittently or continuously, resulting in an environmental pollution and/or an economical loss. Even if the impure solvent is refreshed at a recovery plant located remote from the said manufacture plant, an undesirably high transportation cost will be incurred.